Page:Popular Science Monthly Volume 48.djvu/822

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740
THE POPULAR SCIENCE MONTHLY.

"On the 5th of May, 1881, we inoculated, by means of a Pravaz syringe, twenty-four sheep, one goat, and six cows, each animal with five drops of an attenuated culture of the anthrax bacillus. On the 17th of May we reinoculated these animals with a second virus, also attenuated, but more virulent than the first.

"On the 31st of May we proceeded to make a very virulent inoculation in order to test the efficacy of the preventive inoculations made on the 5th and 7th of May. For this experiment we inoculated the thirty vaccinated animals, and also twenty-four sheep, one goat, and four cows which had not received any previous treatment.

"The very virulent virus used on the 31st of May was obtained from spores preserved in my laboratory since the 21st of March, 1877.

"In order to make the experiments more comparable, we inoculated alternately a vaccinated and a non-vaccinated animal. When the operation was finished, all those present were invited to reassemble on June 2d—i. e., forty-eight hours after the virulent inoculation was made.

"Upon the arrival of the visitors on June 2d, all were astonished at the result. The twenty-four sheep, the goat, and the six cows which had received the attenuated virus all presented the appearance of health. On the contrary, twenty of the sheep and the goat which had not been vaccinated were already dead of anthrax; two more of the non-vaccinated sheep died before the eyes of the spectators, and the last of the series expired before the end of the day. The non-vaccinated cows were not dead. We had previously proved that cows are less subject than sheep to die of anthrax. But all had an extensive œdema at the point of inoculation, behind the shoulder. Certain of these œdematous swellings increased during the following days to such dimensions that they contained several litres of liquid, deforming the animal. One of them even nearly touched the earth. The temperature of these cows was elevated 3° C. The vaccinated cows did not experience any elevation of temperature, or tumefaction, or the slightest loss of appetite. The success, therefore, was as complete for the cows as for the sheep."

Subsequent experience has fully established the value of protective inoculations in this disease, and the method of Pasteur has been practiced on a large scale in France, Austria, Russia, and Switzerland.

The results of anthrax inoculations made in France by Pasteur 's method during twelve years were summarized by Chamberland in 1894. The veterinarians who made the inoculations were each year called upon to answer the following questions: 1. Number of animals inoculated. 2. Number of deaths from first